I do not have any problems with seam gen at all. But the deployment to Jboss failed with the above mentioned bug. By reading about JPA annotation with JEE 5.0 and Hibernate, I asked myself the same question. Why does it not work? Maybe: I am using jboss-4.2.0.GA and jboss-4.2.0.GA that comes with different Hibernate version than the one comes with jboss-seam-2.0.0CR2 (hibernate version 3.2.5) How can I check hibernate version that comes with jboss-4.2.0.GA? Thanks, -b View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4093659#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...